2023 World Conference on Lung Cancer (Posters)-P1.22. Ventana ALK (D5F3) Immunohistochemistry Improves the Accuracy of Pathologic Assessment after Neoadjuvant ALK-TKIs for ALK-Positive NSCLC

P1.22. Ventana ALK (D5F3) Immunohistochemistry Improves the Accuracy of Pathologic Assessment after Neoadjuvant ALK-TKIs for ALK-Positive NSCLC - PDF(Slides)

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A study conducted at Guangdong Provincial People's Hospital in China aimed to improve the accuracy of pathologic assessment after neoadjuvant ALK-TKIs for ALK-positive non-small cell lung cancer (NSCLC). The researchers utilized Ventana ALK (D5F3) immunohistochemistry to assist in determining the presence and quantity of residual viable tumor cells.<br /><br />The study included 24 patients with stage IIA-IIIB ALK-positive NSCLC who received neoadjuvant ALK-TKIs followed by surgery. The initial pathology diagnosis based on biopsies confirmed different types of adenocarcinomas. After neoadjuvant therapy, the researchers observed various morphological changes in tumor cells, including decreased tumor cytoplasm, reduced or disappeared intracytoplasmic mucin, mild morphology of tumor cells, and varying amounts of fibrous hyperplasia.<br /><br />With the use of Ventana ALK (D5F3) immunohistochemistry, the researchers were able to differentiate tumor cells from reactive pneumocytes. ALK staining highlighted tumor cells while reactive pneumocytes showed negative staining. This helped prevent missed diagnoses, as some tumor cells resembled reactive pneumocytes on regular H&E staining slides.<br /><br />The study found that 4 out of 6 cases of invasive mucinous adenocarcinomas transformed into non-mucinous adenocarcinomas after neoadjuvant ALK-TKIs, and 2 cases transformed into mixed adenocarcinomas. Additionally, 4 cases of mixed adenocarcinomas transformed into non-mucinous adenocarcinomas after neoadjuvant ALK-TKIs.<br /><br />Ventana ALK (D5F3) immunohistochemistry improved the accuracy of pathologic assessment after neoadjuvant ALK-TKIs for ALK-positive NSCLC. The study recommends using this technique to help confirm major pathologic response (MPR) and pathologic complete response (PCR) in future pathological assessment work. The MPR rate in the study was 45.8% and the PCR rate was 4.2%.

Asset Subtitle

Li-Xu Yan

Meta Tag

Speaker Li-Xu Yan

Topic Pathology & Biomarkers: Genetic Biomarkers

Keywords

Guangdong Provincial People's Hospital

China

pathologic assessment

neoadjuvant ALK-TKIs

ALK-positive non-small cell lung cancer

NSCLC

Ventana ALK (D5F3) immunohistochemistry

residual viable tumor cells

morphological changes

reactive pneumocytes